When trying to ID irises, it is also important to note whether your plants have purple-based foliage. This can sometimes fade or vice versa get darker during the season, but it is best to look before and during bloom.
A few irises have purple on their stalks or spathes.
This helps to eliminate all those possible irises that are totally green.
Noting the flower count per stem is very useful info. Also note whether flowers on the same stalk tend to open one at a time or multiple flowers at the same time.
You can't go by the color on your computer screen when trying to match. Computer screens and digital cameras both vary in the colors they show to some degree. If you use a non-digital camera, the film that you select will determine the colors you get on print paper (Fugi tends to show yellow greens better than some other, however I could see the difference between slide and print film in the same brand)
Height can vary depending on your weather, warm or cool.
In some cultivars, petal color can be impacted by warm or cool temps at two different times, while the buds are developing (cool weather tends to brighten the color and very warm to hot weather tends make flowers less bright) and then after the flower opens (some fade and other cultivars do not).
If you think you know what you have, it is best to buy the same iris from a reputable grower (who offers to replace or refund if the iris you buy from them is misID'd) to compare it to. On the surface it seems silly to duplicate, but quite often you will notice difference when you grow two side by side and you will know that the two are different.
Good luck!
